Photographic objective for taking or projection



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Aug. 4, 1959 J. BERGER ETAL PHOTOGRAPHIC OBJECTIVE FOR TAKING 0R PROJECTION Filed March 23. 1956 2 Shee's-Sheet 1 1959 J. BERGER EI'AL 2,897,723

PHOTOGRAPHIC OBJECTIVE FOR TAKING 0R PROJECTION Filed March as, 1956 2 Sheets-Sheet 2 United States Patent 2,897,723 PHOTOGRAPHIC OBJECTIVE FOR TAKING 0R PROJECTION Johannes Berger, Heidenheim (Brenz), and Guenther Lange, Konigsbronn, Germany, assignors to Carl Zeiss, Heidenheim (Brenz), Wurttemberg, Germany ApplicationMarch 23, 1956, Serial No. 573,367 Claims priority, application Germany April 7, 1955 9 Claims. (Cl. 88-57) The present invention concerns photographic objectives which are used preferentially for projection; it is however self-evident that one may use them also for photographic exposure with the ray-path inverted.

Object of the invention is an improvement of such objectives which contain six lenses of which the first and the second are collective lenses, the third and the fourth are dispersive lenses and the fifth and the sixth are collective lenses again, wherein all surfaces whose radius of curvature is numerically smaller than 90% of the focal length turn their concave sides towards the air space found between the third and the fourth lenses.

In order to obtain a good compromise between the aberrations influencing the quality of definition in the sense specifically to keep all of them as small as possible the following conditions should be simultaneously fulfilled in objectives of the design mentioned above according to the invention:

wherein the symbols have the significance listed as follows:

f=the focal length of the objective,

L=the arithmetic means of the absolute amounts of the radius of the front surface of the second lens and the radius of the rear surface of the fifth lens,

D =the axial separation of these two surfaces,

L=the arithmetic means of the absolute amounts of the radii of the surfaces r and r bordering upon the diaphragm D =the length of the diaphragm space=d L=the overall length of the objective=the axial separation of the two external surfaces.

In practical performances the second lens may be cemented to the third lens and also the fourth lens to the fifth lens as the case may be.

Further it is an advantage in objectives according to the invention to select the n-value of the fourth lens greater than the arithmetical mean of the n-values of the two neighbouring lenses, particularly the n-value of the fourth lens may even be greater than the n-value of the third lens taken by itself.

Four embodiments of objectives in which the charac- 2,897,723 Patented Aug. 4, 1959 teristics according to the invention are fulfilled are represented in Figures 1 to 4 of the acompanying drawings. They correspond in their design to the numerical values given in the following tables wherein a focal length of f=1 has been made the basis for these numerical values. In the following tables there are designated Table l Lenses Radii Axial Sepam n rations di=0.010 1. 74796 44. 9 r2 =+1.53990 dz=0.001 rs =+0.39242 da=0.160 1. 69368 55. 1 r4 3.548l0 di=0.0237 1. 65533 38. 6 n =+0.24760 ds=0.262 n =0.33982 Lrv d=0.020 1. 76167 27.8

n =+1.0000 Lv d1=0. 118 1. 70594 41. 2

dg=0.009 ro =+l.5399 Ln do=0.2?0 1. 74796 44. 9

Table 2 Lenses Radii Axial Sepan v rations ri =+0.69783 I di=0.070 1. 74796 44. 9

d=0.00l r: =+0.39242 Ln dz=0.1135 1. 69368 55. 1

n w 1 di=0.070 1. 65533 38. 6

d5==o.2650 n =-0.34974 11 v di=0.020 1. 76167 27. 8

r =+0.70795 Lv d =0.120 1. 70594 41. 2

da=0.0880 fn=+1.60790 Lvz dn=0.070 1. 74796 44. 9

Table 3 Lenses Radii Axial Sepam o rations r1 =+0.66834 In d1 =0.0550 1. 69368 55. 1

dz=0.001 n =+0.87584 Ln da =0.140 1. 62287 60. 5

=3.5481 Lm d4 =0.036 1. 56432 45. 5

d5 =0.250 n 0.33256 L v d5 =0.032 1. 76861 26. 8

d1 =0.003 ra =+1.1060 Lv d5 =0.133 1.67133 42. 1

dn =0.103 no=+1.3924 Lvr d1u=0.060 1. 74796 44. 9

1. A photographic objective for taking or projection containing six lenses of which the first and the second are collective lenses, the third and the fourth are dispersive lenses and the fifth and the sixth are collective lenses wherein all surfaces whose radii of curvature are numerically smaller than 90% of the focal length turn their concave side towards the air space found between the third and the fourth lenses characterized in that the following conditions are simultaneously fulfilled:

the symbols having the significance as follows:

f=the focal length of the objective,

;,-=the arithmetic mean of the absolute amounts of the radius of the front surface of the second lens and the radius of the rear surface of the fifth lens,

D,=the axial separation of these two surfaces,

; =the arithmetic mean of the absolute amounts of the radii of the surfaces r and r bordering upon the dia- D =the length of the diaphragm space=d L=the overall length of the objective=the axial separation of the two external surfaces.

2. An objective according to claim 1 characterized in that the second lens is cemented to the third.

3. An objective according to claim 1 characterized in that the fourth lens is cemented to the fifth.

4. An objective according to claim 1 characterized in that the n-value of the fourth lens is greater than the arithmetical mean of the n-values of the two neighbouring lenses, i.e.

5. An objective according to claim 1 characterized in 4 that the p-value of the fourth lens is greater than the nvalue of the third lens.

6. An objective according to claim 1, characterized in that the individual refractive powers of the surfaces (An/r) differ by a maximum of :OJ/f each and the apical separations of the individual surfaces (d) differ by a maximum of $0.054 each from the numerical values taken from the following table:

Lenses Radll Apical Sepana 0 An/r rations n =+0.66834-j +1.119130/f L1".-- d1=0.010-j 1. 747% 4a 9 n =+1.53990-f 0.485720/f n .767697 LIL-.- dZ=0.160-f 1.69368 55.1

n =-3.54s10-] +0.010809/f L111--- d =0.0237-f 1. 65533 38.6

n =-0.339s2 -2.241392/f L1V d.=0.020-] 1. 76167 27.8

n =+1.000o-,r 0.055730/f Lv...-- d1=0.118-f 1. 70594 41. 2

+1 5309 f dazo'oog'j +0 485720/1 m=-0.s175aj +0.914913/j wherein:

L; L are the lenses r .r aretheradii d d are the lens thicknesses of and the air spaces between the lenses,

n are the refractive indices,

v are the Abbe numbers, and

f is the focal length of the objective.

7. An objective according to claim 1, characterized in that the individual refractive powers of the surfaces (An/r) differ by a maximum of :0.5/; each and the apical separations of the individual surfaces (d) differ by a maximum of 10.05 each from the numerical values taken from the following table:

Lenses Radii Apical Sept 11. v A n/r rations n =+0.69783J 1.071836 Lr.---- d1=0.070-f 1. 74796 44. 9 U n 1.7529-f 0.426699/f +0 39242 dz=0.001-j n 1.767697 1411---- d:=0.l135-f 1.69368 55. 1 U :1 0.000000 Lm--- d4=0.070-f 1. 65533 38. 6

n =+0.24760;f -2.646728/f d6=0.2650-f n =0.34974-j 2.l778l7/f L v--- +o 70795 d =0.020-] 1. 76167 27. 8 0 O 8 20 n 7 1 Lv---. d1=0.120-j 1. 70594 41. 2

n =-0.4731w +1.492000/f du=0.0380-f n =+1.607 90-j +0.465178/f Lvr. d|=0.070-f 1. 74796 44. 9

- m=-0.81752-j +0.914913/f wherein:

8. An objective according to claim 1, characterized in that the individual refractive powers of the surfaces asovgpa (An/r) differ by a maximum of iOJ/f each and the apical separations of the individual surfaces (d) diifer by a maximum of 10.054 each from the numerical values taken from the following table:

Lenses Radii Apical Sepam u A 13/1 rations L1... I d1=-0.0550-f 1.69368 55.1 4/] n=+0.37584-f +1.657274/f LIL.-- d1=0.140-f 1. 62287 60.6

n=3.5481-f +0.016502/I L111. d =0.036-f 1. 56432 45. 6

r =+0.23885-f d 0250! 4.302054 n=--0.33256J 2.311191/f LlV--- a.=0.032 1. 76861 28.8

n=+1.1060-f +0.606989/f Lv--. a.=0.133-/ 1.67133 42.1

n= -0.427s1 1 d 0 m3 +1.569224/f 2 r11=-1.1060-f +0.676275/f wherein: 1

L L are the lenses, r are the radii,

"1 d d are the lens thicknesses of and the air spaces between the lenses, n are the refractive indices, v are the Abbe numbers, and

f is the focal length of the objective.

values taken from the following table:

Lenses Radil Apical Sepa- 71 u A n/r rations r1==+0.67803'/ +1.0273l4/f L1--- d1=O.055-f 1. 69656 53. 7

r:=+2.3375'f -0.297989/f d: =0.001-f rs==+0.39811-f +1.571274/f 1111--.. d;=0.l48-f 1. 62554 58. 1

r= 3.0287f +0.020213/f L111. d =0.028-f 1. 56432 45. 3

r =+0.25300-f 2.2305l3/f d;=0.266-f rq== 0.32081-f -2.s74209/! LIV. d0=0.030-f I. 76167 27. 8

r =+1.0000-f -0.761670/f d1=0.020-f r|=+1.2172-f +0.52457 7/ f Lv---- ds=0.110-f 1. 66999 48. 4

n= -0.3896l-f +1.719642/f |=0.150-f r10==+1.3335-f +0.560899/f L111. d10=0.070-f 1. 74796 44. 9

fu -1.17154 +0.638464If wherein:

L L are the lenses, r r are the radii, d

1 d are the lens thicknesses of and the air spaces between the lenses, n are the refractive indices, v are the Abbe numbers, and

f is the focal length of the objective.

References Cited in the file of this patent UNITED STATES PATENTS 

